(1) Field of the Invention
The present invention relates to cephalosporin derivatives and their non-toxic salts having excellent antibacterial activity and good oral absorptivity.
(2) Prior Art
There are disclosed oral cephalosporin derivatives having a 2-carboxymethoxyimino-2-(2-aminothiazol-4-yl)acetamido group at the 7-position of the cephem nucleus (EP patent 210,078A) and having a non-substituted alkylthio group at the 3-position of the cephem nucleus (Japanese Patent Kokai 56-65,095). In addition, among cephalosporin drugs used clinically for oral administration are cephalexin, cefachlor, cefixime and the like. However, these prior art oral cephalosporin derivatives are insufficient in terms of antibacterial activity and antibacterial spectrum against various pathogenic bacteria compared with the cephalosporins developed recently for parenteral administration.
Under such circumstances, it is desired to discover new oral cephalosporin drugs having stonger antibacterial activity and wider antibacterial spectrum.